"What's the Wi-Fi password?" If you're like us, you've heard this shouted throughout your house many times. It might be your kid or grandchild, or their friends. Or, worse, you might find yourself shouting it, too.

There is a solution. You can stick a QR Code around your house, so your guests (and you) can just scan it with an Android phone. It's a secure shortcut with your password hidden inside it. When you need it, you scan the QR Code instead of typing in your password.

If you think you don't know what a QR Code is, you do. (See photo above.) It's that odd-looking box that's filled with smaller boxes, which you may have seen people scanning for discounts at the supermarket.